1. Field of the Invention
The present invention relates to optical fiber connector assembly, and particularly to an optical fiber connector with simplified assembly mechanism having an improved mode marking feature.
2. Description of the Prior Art
As described in U.S. Pat. No. 4,979,792 to Weber et al., the optical fiber plug connector which meets the requirements of Fiber Distributed Data Interface (FDDI) standard, is required to be adapted with interchangeable keying elements which are different from one another to individually and detectably mate with the different corresponding projections in different type receptacle connectors for accommodating the different users needs. In Weber, means applied to the connector for keeping the keying elements with the connector assembly while they are not being used in the passage, is taught to prevent missing of the plural keying elements due to inadvertent misplacing of the key elements.
Referring to Abstract of U.S. Pat. No. 5,041,025 to Haitmanek, a multi-positionable key element, in place of the plural key elements used before, is positionable in plural different orientations to provide keyways each of which uniquely accommodate one of the key projections defining the plural different key positions of the receptacle connector wherein rotative movement of the key element within the plug connector provides the plural different orientations and thereby the plural keyways.
The multi-positionable key element disclosed in Haitmanek still has some disadvantages. First, because the key element is attached to the connector housing by the engagement of an internal threaded aperture with a threaded screw, the user needs to fasten or loosen the key element by a screw driver when changing the operative surfaces of the key element. Sometimes, an appropriate driver may not be easily obtained during timely switching operation, so it delays the operation and frustrates the operator.
Second, in the second from the last paragraph of Haitmanek, the housing can not be assembled together without use of the securement screw and the key element therein so that during the operative surface change of the key element, the securement and the whole character of the connector assembly is effected until the key element is again fixedly attached to the housing by the screw. Some of the internal elements of the connector assembly may move to improper positions when the connector assembly is in a non-assembled condition during changing the operative surfaces of the key element, and it will influence the accurate and strict relationship among the assembled elements in the re-assembled whole connector assembly.
Third, the key element in Haitmanek uses a T-shaped structure incorporating the complementary configuration in the housing to define four different keyways by means of three different rotation positions about the vertical axis through which the screw extends and one upside-down position by rotation about a horizontal axis. This multi-direction of rotation about different axes tends to confuse the user and complicate the switching operation. Additionally, the single T-shaped configuration surface of the key element is designedly utilized to define three separate keyways by rotation about a vertical axis, and is symmetric itself, so that the user can not easily and understandably exactly know how to rotatively reposition the key element to obtain its designated positions engaging the corresponding different key projections of the complementary receptacle connectors when there is no visible mark to indicate the rotation or positioning of the key element.
Therefore, it is desirable to provide a connector assembly having a single key which provides not only plural mutually exclusive key positions, but also the functions of independent enclosure within the housing for not effecting the whole securement of the connector assembly during the operative surface change of the key, of easy switching the operative surfaces of the key element, and of easily understandable way to show how to position the key element in its desired positions to meet the corresponding key projections of the receptacle connectors.